Art of pressure distillation



Mav 6. 1930.. N. E. LOOMIS ART OF PRESSURE DISTILLA'I ION Filed May 16, 1922 lll I IIIIII Patented May 6, 1930 UNITED STATES PATENT OFFICE NATHANIEL E. LOOMIS, OF ELIZABETH, NEW" JERSEY, ASSIGNOR TO STANDARD OIL DEVELOPMENT COMPANY, A CORPORATION OF DELAWARE mm or rnnssuan nrs'rrnnn'rrou Application filed May 16, 1922. Serial No. 561,407.

This invention relates to the art of pressure distillation or pyrolytic conversion of heavy petroleum oils into lighter products, and particularly to improvements in methods and apparatus of the general character set forth in Patent 1,405,286. The invention will be fully understood fromthe following description taken in connection with the accompanying drawing which represents a side eleo vation, partly in section, of an embodiment of my invention.

. Referring more particularly to the drawing, the letter A designates generally a. pressure-still, preferably of the type comprising 16 a horizontal cylindrical drum 1 and a bank of tubes 2 connected. thereto by legs 3, the

tubes beingmounted in a furnace firedby coal or by oil-burners as desired. Leading from th'e'still is a vapor-connection i opening into an intermediate drum 5 which may conyeniently be of horizontal cylindrical form, and which contains baifle-spreaders 6 fora pur ose to be referred to hereinafter, these pre erably being of such construction and i 2 mounting as to be readily removable, inorder to facilitate cleaning of the drum when necessary. A vapor connection 7 opens into a final drum 8 supported on a suitable mounting (not' shown, for simplicity), and containing a transverse tube-sheet 9 in which are tapped horizontal pipes 14 having small perforations for the escape of vapors, as will later be referred to in detail. Spaced from k the tube sheet is a'false-head 10 with a free vapor passageway over its upper edge.

Leading through the tubesheet 9 and falsehead 10 is an overflow pipe 11 which extends downthrough the vapor connection to ter minate within the distributor-trough 12, the pipe dipping beneath the liquid-surface suf- 'ficiently to form a seal against any possible back-flow of vapors from drum 8.

A feed-pipe 13 is tapped into the drum 8,

- also a draw-oifpipe 21; and a similar drawoif pipe may-be provided in drum 5 if desired. The drum 8 thus can operate as a feed-oil container, and also perform further functions as will be shown hereinafter.

The drums are lagged with any suitable layered, cellular or solid insulation 19, and

are provided with manheads.

Leading from the drum 8 is a vapor-line 16 connecting with a water-cooledcondenser 17, andthe usual receiver equipment, shown con- 5 ventionally at 18. .7

The usual equipment of gauges, pyrometers, release and safety valves, etc., is applied'throughout the system.

Using the apparatus above described, the procedure may be as follows The still is charged, usually with gas oil, and is fired at the start under atmospheric pressure until any traces of wa-ter or light hydrocarbons pass over. These so-called drips may be directly continuously drained out from drum 8 by the pipe 21,-and having beenelimin'ated, the drain-valve is then closed and the receiver may nowbe connected in on the high-pressure gas manifold, where stills are being 0 erated in a battery, and the gas passing bacE through the vaporline 16 and check-valve 20 will initially-provide the-necessary operating pressure, for example lbs. gauge-pressure. The firing of the still cannow be pushed until the oil temperature reaches about 725 F. or more. At first, the vapors coming up from the still, will almost wholly condense in the drums, the heaviest fractions and liquid or mist particles swept along by the vapors dropping out especially in drum-5,.the remaining vapors then passing on into drum '8'. The vapors then displacing thejaccumulating oil between false-head 10 and tube-sheet 9 enter the tubes 14 and escape by bubbling. up through the accumulating liquid body. V

A temperature level 1s presently reached where only relatively heavy hydrocarbons are condensed and retained in the oil body, while the gasoline vapors are allowed to" pass on through the vapor-line 16 to the water-cooled condenser 17 and the receiver. As the condensation' in the drum 8 adds to the liquid,- overflow begins down through pipe 11. The 9 desired running conditions having now been the receiver, so as to maintain the volume in the system constant, and therun is so continued until it is necessary to stop for cleaning. The overflow, consisting of feed-stock and heavy condensates, passing down by pipe 11 distributes from trough 12 so as to flow down the Spreaders 6 in a comparatively thin film where it is heated bothindirectly by the bottom heat of conduction through the spreader platesfrom vapors passing underneath, and-especially, directly by the vapors passing over the thoroughly exposed-surface. Any lighterconstituents held are thus here revaporized and released to pass on to the condenser system, and the remaining liquid flows on down to thestill, being sufiiciently heated first in drum 8 and finally in drum to enter the still without a retardant cooling of the charge therein. At the same time the vapors fresh from the still entering drum 5 drop out their heaviest constituents to reflux to the still, likewise entrained liquid particles carried up from the still by the rush of vapors.

- the oil.

. claim all inherent novelty as broadly as the As a result of all this, the final drum 8 is 7 kept free iromgthe heaviest reflun, andalso runs at such a temperature' level that it isle'rF abled to effect a relatively close final separation.

As, a furthermeans of adjustingjhe temperature'inlirum 8, there is provideda coil 15,

through-which may be circulated a cooling medium, such as an oil of suitable temperature, or preferably water.

The initial detailof operation may be modified slightly, if. desired, by charging both drum 8 and still 1 at the start. After firing as usual and putting the still up to running pressure'and temperature, the vapors reaching drum 8 displace the'liquid between the false-head 10 and tube-sheet 9, and enter the tubes 14 and escape by bubbling up through As the oil warms up, a temperature level is reached where only heavier hydrocarbons are condensed and retained in the oil body, while the gasoline vapors are allowed to pass on over to the condenser 17. As the condensation in the drum 8 adds to the liquid and starts the overflow down through pipe .11, the supply of feed stock is begun through the feed line13 at such rate as to compensate for the volume of distillate leaving the sys tem, this and the further detail being as above mentioned.

While in describing my invention I have referred to particular details,.it will be understood that this is for the purpose of illus- .tration and explanation, and in no sense limitative, nor is it dependent upon the accuracy of the theories or reasons which I have advanced to account for the advantageous results attained, but the invention is to be regarded as limited only as defined in the following claims in which it is my intention to prior art-permits.

What I claim is 1. A petroleum distillingapparatus which means for controlling the temperature of the oil in said container.

2. A petroleum distilling apparatus which comprises a still, a series of baflie-spreaders in the path of the outgoing vapors and the incoming feed-oil, a feed-oil container, means for bubbling the vapors through the oil in such containerand a cooling coil in said container.

A petroleum distilling apparatus which comprises a still, a drum for receiving vapors from the still and containing staggered baifles for exposing films of feed-oil to the vapors, and a further drum for containing an overflow body of oil into which the vapors are successively bubbled.

4. A petroleum distilling apparatus, which comprises a still, a drum for receiving vapors from the still and containin staggered baflles for exposing films of fee -oil to the vapors, a further drum for containing an overflow body otoil into which the vapors are successively bubbled, a nd means for introducing feed-coil into said last-named drum.

5. A petroleum distilling apparatus which comprises a still, a feed-oil container, 8. submerged inlet for admitting still-vapors thereinto, means for controlling the temperature of said container and a series of staggered baflles interposed in the path of the vapors between said still and said container.

6. A petroleum distilling apparatus which comprises a still, a heat insulated feed-oil container, a submerged inlet for admitting still-vapors thereinto, a temperature-control-' ling COll 1n said container and a semes of staggered baffles interposed in the path of the vapors between said still and said container.

7. A petroleum distilling apparatus, which comprises a still, a drum for receiving the vapors from the still and containing a series.

' distributor-trough on the uppermost of said baflles, a feed-oil container into which the vapors are successively bubbled, an overflow pipe from said container dipping into said distributor-trough, means for supplying feedoil to said container, and a temperautre-controlling coil in said container.

9. Improvement in the art of pressure distillation of petroleum oils for the purpose of producing lighter products which cornprises passing the rising vapors over counter currently flowing films of oil, thereby separating out and refluxing the heaviest portions of the vapors, bubbling the remaining vapors through a body of oil,-and positively cooling the said body of oil to control the; character of vapors escaping therefrom. 10. Improvement in the art of pressure distillation of petroleum oils for the purpose of produc'in lighter products which comprises passing the rising vapors over counter cur rently flowing films of oil, bubbling the remaining vapors through a body of 011, a part at least of which is provided by introduction of feed stock and positively cooling the said body of oil to control the character of vapors escapingtherefrom.

- NATHANIEL E. LOOMIS. 

